A storm sweeping into New England Friday has the potential to dump two feet of snow and to rank among the 10 biggest on record for the region, weather forecasters say. Already on Thursday major metropolitan areas announced plans to cope with the storm, from school cancellations and parking bans to public assurances that enough salt has been stockpiled.

Whether the snow piles up to the two-foot level won’t be known until Saturday morning, but officials across the region are urging residents to be prepared – to have canned goods and flashlights at the ready and to be cautious about travel on Friday and Saturday.

The storms is expected to build up late Friday, and continue overnight, with wind and continued snow or ice lingering as a travel concern on Saturday.

Winds in the region are forecast to include gusts up to 75 miles per hour. That, coupled with the potential snowfall and some freezing rain, could ground aircraft, stall commuters, and complicate railroad operations across the region.

It also makes for a significant risk of power outages.

A Weather Service alert for the Boston area says snow will start to develop Friday morning, shifting to rain during the afternoon. “The rain will change back to wet snow sometime Friday night, and continue into Saturday afternoon.”

In Boston, Mayor Thomas Menino showed by mid-day Thursday how seriously the region is taking the storm. The city announced that schools would be closed Friday, declared a snow emergency and put a parking ban in place for noon Friday, and said only "essential" workers should show up at City Hall.

Via Twitter, the city warned of a “historic winter blizzard,” although it’s possible accumulations in the city will end up closer to 10 inches than 20.

The storm, dubbed Nemo, comes just a few months after the New York City area was hit by Sandy, the so-called superstorm that brought significant floods and power outages.

“We’re ready for #Nemo, the office of New York City Mayor Michael Bloomberg said on Twitter. “We have 250,000+ tons of salt on hand, 350 salt spreaders & plows ready to be put on 1,800 Sanitation trucks.”

The city has some 6,300 street miles to be plowed.

Forecasts for Nemo are based on a confluence of two main forces: a cold front pushing down from Canada and lots of moisture moving up through the southern states.

Although the storm’s impact during the early part of the work day may prove modest, many residents in the region will opt to be telecommuters on Friday – with encouragement from their employers.

If the storm ends up being big, the timing has a silver lining – Saturday is automatically a day off from school and work for most people.

The epic “Blizzard of 1978,” by contrast, involved two-foot-plus snowfalls in cities including Boston on a Monday and Tuesday.

So far, major airlines are responding to Nemo’s threat by offering passengers a free opportunity to change their travel plans. The website Weather Underground has compiled some of the details, as of Thursday morning.